Alert archive / Iowa / Tornado Warnings in 2020

Tornado Warning 9, NWS Des Moines, IA

May 26, 2020Boone County, Dallas County, Iowa

NWS Des Moines, IA issued this tornado warning at May 26, 2020, 1:49 PM CDT for Boone County, Dallas County, Iowa. It was in force for 26 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: May 26, 2020, 1:49 PM CDT (18:49 UTC)
Expired: May 26, 2020, 2:15 PM CDT
In force: 26 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

Counties Boone County, IA, Dallas County, IA

The radar

The Des Moines radar (KDMX), 29 km from the middle of the area, began a volume at 18:54 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 26, 1:20 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 6.8 hours before the alert went out and 206 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 534 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 70 m²/s²
0-3 km storm-relative helicity: 130 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

202 
WFUS53 KDMX 261849
TORDMX
IAC015-049-261915-
/O.NEW.KDMX.TO.W.0009.200526T1849Z-200526T1915Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
149 PM CDT Tue May 26 2020

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Southwestern Boone County in central Iowa...
  North central Dallas County in central Iowa...

* Until 215 PM CDT.
    
* At 149 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Woodward, or 7 miles southeast of Perry, moving
  north at 25 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This tornadic thunderstorm will remain over mainly rural areas of
  southwestern Boone and north central Dallas Counties, including the
  following locations... Berkley and Bouton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4180 9393 4180 9404 4201 9416 4201 9397
TIME...MOT...LOC 1849Z 162DEG 20KT 4178 9397 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

Martin

2 follow-up statements

463 
WWUS53 KDMX 261905
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
205 PM CDT Tue May 26 2020

IAC049-261914-
/O.CAN.KDMX.TO.W.0009.000000T0000Z-200526T1915Z/
Dallas IA-
205 PM CDT Tue May 26 2020

...THE TORNADO WARNING FOR NORTH CENTRAL DALLAS COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 800 PM CDT for central Iowa.

LAT...LON 4201 9416 4201 9397 4186 9394 4186 9408
TIME...MOT...LOC 1904Z 162DEG 23KT 4189 9402 

$$

IAC015-261915-
/O.CON.KDMX.TO.W.0009.000000T0000Z-200526T1915Z/
Boone IA-
205 PM CDT Tue May 26 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 215 PM CDT FOR
SOUTHWESTERN BOONE COUNTY...
    
At 204 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Perry, moving north at 25 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
Berkley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4201 9416 4201 9397 4186 9394 4186 9408
TIME...MOT...LOC 1904Z 162DEG 23KT 4189 9402 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

Martin

077 
WWUS53 KDMX 261913
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
213 PM CDT Tue May 26 2020

IAC015-261923-
/O.EXP.KDMX.TO.W.0009.000000T0000Z-200526T1915Z/
Boone IA-
213 PM CDT Tue May 26 2020

...THE TORNADO WARNING FOR SOUTHWESTERN BOONE COUNTY WILL EXPIRE AT
215 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until 800 PM CDT for central Iowa.

LAT...LON 4201 9416 4201 9397 4186 9394 4186 9408
TIME...MOT...LOC 1913Z 162DEG 20KT 4193 9404 

$$

Martin

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 26, 1:25 PM CDT	Tornado Warning Tornado observed	DMX	Dallas	35 min
May 26, 2:22 PM CDT	Tornado Warning	DMX	Poweshiek, Tama	38 min
May 26, 2:25 PM CDT	Tornado Warning	DMX	Boone, Webster	35 min
May 26, 3:47 PM CDT	Tornado Warning	DMX	Humboldt, Wright	13 min
May 26, 3:57 PM CDT	Tornado Warning	DMX	Audubon, Guthrie	21 min
May 26, 4:23 PM CDT	Special Weather Statement	DMX	Mahaska	22 min
May 26, 5:16 PM CDT	Tornado Warning	DMX	Franklin, Wright	29 min
May 26, 6:09 PM CDT	Special Weather Statement	DMX	Cerro Gordo, Worth	51 min
May 26, 6:30 PM CDT	Severe Thunderstorm Warning	DMX	Worth	30 min

Nearby

Tornado Warnings in Iowa, 2020 Every tornado warning in 2020 Tornadoes in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.